//===--- RISCVToolchain.cpp - RISC-V ToolChain Implementations --*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

#include "RISCVToolchain.h"

#include "CommonArgs.h"

#include "clang/Driver/Compilation.h"

#include "clang/Driver/InputInfo.h"

#include "clang/Driver/Options.h"

#include "llvm/Option/ArgList.h"

#include "llvm/Support/FileSystem.h"

#include "llvm/Support/Path.h"

#include "llvm/Support/raw_ostream.h"

using namespace clang::driver;

using namespace clang::driver::toolchains;

using namespace clang::driver::tools;

using namespace clang;

using namespace llvm::opt;

static void addMultilibsFilePaths(const Driver &D, const MultilibSet &Multilibs,

                                  const Multilib &Multilib,

                                  StringRef InstallPath,

                                  ToolChain::path_list &Paths) {

  if (const auto &PathsCallback = Multilibs.filePathsCallback())

    for (const auto &Path : PathsCallback(Multilib))

      addPathIfExists(D, InstallPath + Path, Paths);

}

// This function tests whether a gcc installation is present either

// through gcc-toolchain argument or in the same prefix where clang

// is installed. This helps decide whether to instantiate this toolchain

// or Baremetal toolchain.

bool RISCVToolChain::hasGCCToolchain(const Driver &D,

                                     const llvm::opt::ArgList &Args) {

  if (Args.getLastArg(options::OPT_gcc_toolchain))

    return true;

  SmallString<128> GCCDir;

  llvm::sys::path::append(GCCDir, D.Dir, "..", D.getTargetTriple(),

                          "lib/crt0.o");

  return llvm::sys::fs::exists(GCCDir);

}

/// RISC-V Toolchain

RISCVToolChain::RISCVToolChain(const Driver &D, const llvm::Triple &Triple,

                               const ArgList &Args)

    : Generic_ELF(D, Triple, Args) {

  GCCInstallation.init(Triple, Args);

  if (GCCInstallation.isValid()) {

    Multilibs = GCCInstallation.getMultilibs();

    SelectedMultilibs.assign({GCCInstallation.getMultilib()});

    path_list &Paths = getFilePaths();

    // Add toolchain/multilib specific file paths.

    addMultilibsFilePaths(D, Multilibs, SelectedMultilibs.back(),

                          GCCInstallation.getInstallPath(), Paths);

    getFilePaths().push_back(GCCInstallation.getInstallPath().str());

    ToolChain::path_list &PPaths = getProgramPaths();

    // Multilib cross-compiler GCC installations put ld in a triple-prefixed

    // directory off of the parent of the GCC installation.

    PPaths.push_back(Twine(GCCInstallation.getParentLibPath() + "/../" +

                           GCCInstallation.getTriple().str() + "/bin")

                         .str());

    PPaths.push_back((GCCInstallation.getParentLibPath() + "/../bin").str());

  } else {

    getProgramPaths().push_back(D.Dir);

  }

  getFilePaths().push_back(computeSysRoot() + "/lib");

}

Tool *RISCVToolChain::buildLinker() const {

  return new tools::RISCV::Linker(*this);

}

ToolChain::RuntimeLibType RISCVToolChain::GetDefaultRuntimeLibType() const {

  return GCCInstallation.isValid() ?

    ToolChain::RLT_Libgcc : 
ToolChain::RLT_CompilerRT1
;

}

ToolChain::UnwindLibType

RISCVToolChain::GetUnwindLibType(const llvm::opt::ArgList &Args) const {

  return ToolChain::UNW_None;

}

void RISCVToolChain::addClangTargetOptions(

    const llvm::opt::ArgList &DriverArgs,

    llvm::opt::ArgStringList &CC1Args,

    Action::OffloadKind) const {

  CC1Args.push_back("-nostdsysteminc");

}

void RISCVToolChain::AddClangSystemIncludeArgs(const ArgList &DriverArgs,

                                               ArgStringList &CC1Args) const {

  if (DriverArgs.hasArg(options::OPT_nostdinc))

    return;

  if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {

    SmallString<128> Dir(getDriver().ResourceDir);

    llvm::sys::path::append(Dir, "include");

    addSystemInclude(DriverArgs, CC1Args, Dir.str());

  }

  if (!DriverArgs.hasArg(options::OPT_nostdlibinc)) {

    SmallString<128> Dir(computeSysRoot());

    llvm::sys::path::append(Dir, "include");

    addSystemInclude(DriverArgs, CC1Args, Dir.str());

  }

}

void RISCVToolChain::addLibStdCxxIncludePaths(

    const llvm::opt::ArgList &DriverArgs,

    llvm::opt::ArgStringList &CC1Args) const {

  const GCCVersion &Version = GCCInstallation.getVersion();

  StringRef TripleStr = GCCInstallation.getTriple().str();

  const Multilib &Multilib = GCCInstallation.getMultilib();

  addLibStdCXXIncludePaths(computeSysRoot() + "/include/c++/" + Version.Text,

                           TripleStr, Multilib.includeSuffix(), DriverArgs,

                           CC1Args);

}

std::string RISCVToolChain::computeSysRoot() const {

  if (!getDriver().SysRoot.empty())

    return getDriver().SysRoot;

  SmallString<128> SysRootDir;

  if (GCCInstallation.isValid()) {

    StringRef LibDir = GCCInstallation.getParentLibPath();

    StringRef TripleStr = GCCInstallation.getTriple().str();

    llvm::sys::path::append(SysRootDir, LibDir, "..", TripleStr);

  } else {

    // Use the triple as provided to the driver. Unlike the parsed triple

    // this has not been normalized to always contain every field.

    llvm::sys::path::append(SysRootDir, getDriver().Dir, "..",

                            getDriver().getTargetTriple());

  }

  if (!llvm::sys::fs::exists(SysRootDir))

    return std::string();

  return std::string(SysRootDir.str());

}

void RISCV::Linker::ConstructJob(Compilation &C, const JobAction &JA,

                                 const InputInfo &Output,

                                 const InputInfoList &Inputs,

                                 const ArgList &Args,

                                 const char *LinkingOutput) const {

  const ToolChain &ToolChain = getToolChain();

  const Driver &D = ToolChain.getDriver();

  ArgStringList CmdArgs;

  if (!D.SysRoot.empty())

    CmdArgs.push_back(Args.MakeArgString("--sysroot=" + D.SysRoot));

  bool IsRV64 = ToolChain.getArch() == llvm::Triple::riscv64;

  CmdArgs.push_back("-m");

  if (IsRV64) {

    CmdArgs.push_back("elf64lriscv");

  } else {

    CmdArgs.push_back("elf32lriscv");

  }

  CmdArgs.push_back("-X");

  std::string Linker = getToolChain().GetLinkerPath();

  bool WantCRTs =

      !Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles);

  const char *crtbegin, *crtend;

  auto RuntimeLib = ToolChain.GetRuntimeLibType(Args);

  if (RuntimeLib == ToolChain::RLT_Libgcc) {

    crtbegin = "crtbegin.o";

    crtend = "crtend.o";

  } else {

    assert (RuntimeLib == ToolChain::RLT_CompilerRT);

    crtbegin = ToolChain.getCompilerRTArgString(Args, "crtbegin",

                                                ToolChain::FT_Object);

    crtend = ToolChain.getCompilerRTArgString(Args, "crtend",

                                              ToolChain::FT_Object);

  }

  if (WantCRTs) {

    CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crt0.o")));

    CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(crtbegin)));

  }

  AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);

  Args.AddAllArgs(CmdArgs, options::OPT_L);

  Args.AddAllArgs(CmdArgs, options::OPT_u);

  ToolChain.AddFilePathLibArgs(Args, CmdArgs);

  Args.AddAllArgs(CmdArgs,

                  {options::OPT_T_Group, options::OPT_s, options::OPT_t,

                   options::OPT_Z_Flag, options::OPT_r});

  // TODO: add C++ includes and libs if compiling C++.

  if (!Args.hasArg(options::OPT_nostdlib) &&

      !Args.hasArg(options::OPT_nodefaultlibs)) {

    if (D.CCCIsCXX()) {

      if (ToolChain.ShouldLinkCXXStdlib(Args))

        ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);

      CmdArgs.push_back("-lm");

    }

    CmdArgs.push_back("--start-group");

    CmdArgs.push_back("-lc");

    CmdArgs.push_back("-lgloss");

    CmdArgs.push_back("--end-group");

    AddRunTimeLibs(ToolChain, ToolChain.getDriver(), CmdArgs, Args);

  }

  if (WantCRTs)

    CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(crtend)));

  CmdArgs.push_back("-o");

  CmdArgs.push_back(Output.getFilename());

  C.addCommand(std::make_unique<Command>(

      JA, *this, ResponseFileSupport::AtFileCurCP(), Args.MakeArgString(Linker),

      CmdArgs, Inputs, Output));

}

// RISCV tools end.